Display device having a plurality of bank structures

ABSTRACT

The embodiment provides a display device including an array substrate, an opposite substrate, a plurality of micro light-emitting diodes and a plurality of bank structures. The opposite substrate is disposed opposite to the array substrate. The micro light-emitting diodes are arranged in an array on the array substrate, wherein the micro light-emitting diodes are electrically connected to the array substrate. The bank structures are located between the array substrate and the opposite substrate, wherein the bank structures form a plurality of accommodating regions, and one of the micro light-emitting diodes is located in one of the accommodating regions. A height of the bank structures is more than or equal to a height of the micro light-emitting diodes.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefits of U.S. provisionalapplication Ser. No. 62/251,132, filed on Nov. 5, 2015 and Chinaapplication serial no. 201610395404.4, filed on Jun. 6, 2016. Theentirety of each of the above-mentioned patent applications is herebyincorporated by reference herein and made a part of this specification.

BACKGROUND

Field of the Disclosure

The embodiment relates to a display device, and particularly relates toa light-emitting diode display device.

Description of Related Art

Since a light-emitting diode (LED) display device has advantages such asactive light emitting, high brightness, high contrast, and low powerconsumption, and has a longer lifetime compared to an organiclight-emitting diode (OLED) display device, it has become one of thetechnologies of new type displays to develop in recent years.Specifically, the light-emitting diode display device is mainly composedof a thin film transistor array substrate and light-emitting diodesarranged in an array. The optical performance of the light-emittingdiode display device depends on the design of the light-emitting diodesand the optical structure design of the periphery of the light-emittingdiodes. Since the light-emitting diode is a multi-surface light-emittinglight source, lateral light of the light-emitting diode emitting ontothe adjacent light-emitting diode is likely to result in an opticalcross-talk phenomenon after the light-emitting diodes are closelyarranged in an array, which may cause disadvantages, such as colormixing, halo, reduction of screen contrast or fuzziness. Also, it ispossible to reduce color saturation of the light-emitting diode displaydevice when including a wavelength converting material.

SUMMARY

The embodiment provides a display device which has a better opticaldisplay performance.

The display device of the embodiment includes an array substrate, aplurality of micro light-emitting diodes and a plurality of bankstructures. The micro light-emitting diodes are arranged in an array onthe array substrate. The bank structures are located on the arraysubstrate, wherein the micro light-emitting diodes are electricallyconnected to the array substrate. The bank structures form a pluralityof accommodating regions, and one of the micro light-emitting diodes islocated in one of the accommodating regions. A height of one of the bankstructures is more than or equal to a height of one of the microlight-emitting diodes.

The display device of the embodiment includes an array substrate, anopposite substrate, a plurality of micro light-emitting diodes and aplurality of bank structures. The opposite substrate is disposedopposite to the array substrate. The micro light-emitting diodes arearranged in an array on the array substrate. The bank structures arelocated between the array substrate and the opposite substrate. Themicro light-emitting diodes are electrically connected to the arraysubstrate. The bank structures form a plurality of accommodatingregions, and one of the micro light-emitting diodes is located in one ofthe accommodating regions. A height of one of the bank structures ismore than or equal to a height of the one of the micro light-emittingdiodes.

The display device of the embodiment includes an array substrate, anopposite substrate, a plurality of micro light-emitting diodes, awavelength converting enhancement layer, a color filter layer and aplurality of bank structures. The opposite substrate is disposedopposite to the array substrate. The micro light-emitting diodes arearranged in an array on the array substrate. The wavelength convertingenhancement layer is disposed above the opposite substrate. The colorfilter layer is disposed above the opposite substrate and has aplurality of color filter patterns. The bank structures are locatedbetween the array substrate and the opposite substrate. The microlight-emitting diodes are electrically connected to the array substrate.The bank structures form a plurality of accommodating regions, and oneof the micro light-emitting diodes is located in one of theaccommodating regions. A height of one of the bank structures is morethan or equal to a height of the one of the micro light-emitting diodes.

Based on the above, since the display device of the embodiment has thedesign of the bank structures, the optical cross-talk phenomenongenerated by the micro light-emitting diodes arranged in an array on thearray substrate can be effectively reduced. Thereby, the optical displayperformance of the display device of the embodiment can be effectivelyimproved.

In order to make the aforementioned features and advantages of thedisclosure more comprehensible, embodiments accompanied with figures aredescribed in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the embodiments, and are incorporated in and constitutea part of this specification. The drawings illustrate embodiments and,together with the description, serve to explain the principles of theembodiments.

FIG. 1A is a schematic cross-sectional view of a display deviceaccording to an embodiment.

FIG. 1B is a schematic view of a bank structure of an embodiment of thedisplay device of FIG. 1A.

FIG. 1C is a schematic view of a bank structure of another embodiment ofthe display device of FIG. 1A.

FIG. 1D is a schematic view of a bank structure of another embodiment ofthe display device of FIG. 1A.

FIG. 2 is a schematic cross-sectional view of a display device accordingto another embodiment.

FIG. 3 is a schematic cross-sectional view of a display device accordingto another embodiment.

FIG. 4 is a schematic cross-sectional view of a display device accordingto another embodiment.

FIG. 5 is a schematic cross-sectional view of a display device accordingto another embodiment.

FIG. 6 is a schematic cross-sectional view of a display device accordingto another embodiment.

FIG. 7 is a schematic cross-sectional view of a display device accordingto another embodiment.

FIG. 8A is a schematic cross-sectional view of a display deviceaccording to another embodiment.

FIG. 8B is a schematic top view of a patterned reflective layer of FIG.8A.

FIG. 9A is a schematic cross-sectional view of a display deviceaccording to another embodiment.

FIG. 9B is a curve diagram illustrating a relationship betweenwavelength and normalized light intensity of the display device with thewavelength converting enhancement layer and without the wavelengthenhancement converting layer of FIG. 9A.

FIG. 9C and FIG. 9D are schematic views of the wavelength convertingenhancement layers according to two different embodiments in FIG. 9A.

FIG. 10 is a schematic cross-sectional view of a display deviceaccording to another embodiment.

FIG. 11 is a schematic cross-sectional view of a display deviceaccording to another embodiment.

FIG. 12 is a schematic cross-sectional view of a display deviceaccording to another embodiment.

FIG. 13 is a schematic cross-sectional view of a display deviceaccording to another embodiment.

FIG. 14 is a schematic cross-sectional view of a display deviceaccording to another embodiment.

DESCRIPTION OF THE EMBODIMENTS

In the following detailed description, for purposes of explanation,numerous specific details are set forth in order to provide a thoroughunderstanding of the disclosed embodiments. It will be apparent,however, that one or more embodiments may be practiced without thesespecific details. In other instances, well-known structures and devicesare schematically shown in order to simplify the drawing.

FIG. 1A is a schematic cross-sectional view of a display deviceaccording to an embodiment. Referring to FIG. 1A, in the embodiment, adisplay device 100 a includes an array substrate 110, an oppositesubstrate 120, a plurality of micro light-emitting diodes 130 and aplurality of bank structures 140 a 1. The array substrate 110 is a thinfilm transistor (TFT) array substrate, for example. In other words, aplurality of thin film transistors can be arranged on the arraysubstrate 110. The opposite substrate 120 is disposed opposite to thearray substrate 110. The micro light-emitting diodes 130 are arranged inan array on the array substrate 110, wherein the micro light-emittingdiodes 130 are electrically connected to the array substrate 110.Specifically, the micro light-emitting diodes 130 are electricallyconnected to the thin film transistors on the array substrate 110. Thebank structures 140 a 1 are located between the array substrate 110 andthe opposite substrate 120, wherein the bank structures 140 a 1 form aplurality of accommodating regions C. In other words, the plurality ofaccommodating regions C can be separated by the adjacent bank structures140 a 1, and at least one of the micro light-emitting diodes 130 islocated in at least one of the accommodating regions C. A height H1 ofat least one of the bank structures 140 a 1 is more than a height H2 ofat least one of the micro light-emitting diodes 130, and a width of atleast one of the bank structures 140 a 1 can be different. The height H2of at least one of the micro light-emitting diodes 130 may be a distancebetween a top surface of the array substrate 110 and an upper surface132 of at least one of the micro light-emitting diodes 130 as shown inFIG. 1A.

Specifically, referring to FIG. 1A, at least one of the microlight-emitting diodes 130 can be electrically connected to a source or adrain (not shown) of at least one of the thin film transistors (notshown) on the array substrate 110 by a conductive structure (not shown),and at least one of the micro light-emitting diodes 130 can beelectrically connected to a common electrode (not shown) of the arraysubstrate 110 by a conductive structure (not shown). Here, the microlight-emitting diodes 130 are flip-chip micro light-emitting diodes, forexample, and the micro light-emitting diodes 130 specifically includes ablue light micro light-emitting diode 130 a, a green light microlight-emitting diode 130 b, and a red light micro light-emitting diode130 c. The size of the micro light-emitting diodes 130 from top view isbetween 1 micrometer and 1000 micrometers. In an embodiment, the size isbetween 1 micrometer and 100 micrometers. The shape of the microlight-emitting diodes 130 might be a rectangle, a circle or othershapes, and is not limited thereto. The size of the micro light-emittingdiodes 130 from top view can be the longest distance within a profile ofone of the micro light-emitting diodes 130. The profile is defined by anoutline of a projected image of one of the micro light-emitting diodes130 from top view. The height H2 of at least one of the microlight-emitting diodes 130 is between 0.5 micrometers and 500micrometers, for example. In an embodiment, the height H2 of at leastone of the micro light-emitting diodes 130 is between 0.5 micrometersand 30 micrometers, for example. That is to say, the microlight-emitting diodes 130 of the embodiment can emit light withdifferent colors specifically. However, in other embodiments, the microlight-emitting diodes 130 may also emit light with the same color, andis not limited thereto. The opposite substrate 120 may be a cover plate(e.g., transparent substrate) or a color filter substrate, for example.However, in other embodiments, the opposite substrate 120 may also be athin film encapsulation or a protective layer with protective andsupporting effects. The protective layer may be a planarization layer,which can be disposed on the array substrate 110 such that the surfaceof the array substrate 110 is planarized. For example, the protectivelayer may be disposed around the micro light-emitting diodes 130, or maybe disposed above a top surface of the micro light-emitting diodes 130,or further cover on a top surface of the bank structure 140 a 1 awayfrom the array substrate 110. Disposing of the protective layer aroundthe micro light-emitting diodes 130 might leave some space in at leastone of the accommodating regions C, or the protective layer might filledin at least one of the accommodating regions C, and is not limitedthereto. The protective layer may also prevent the invasion of moistureand oxygen. A material of the protective layer comprises a transparentphotoresist, a transparent ultraviolet gel, etc., and is not limitedthereto. The bank structures 140 a 1 of the embodiment are disposedabove the array substrate 110, and at least one of the bank structures140 a 1 includes at least a first bank portion 142 a 1 and a second bankportion 144 a 1, wherein the first bank portion 142 a 1 and the secondbank portion 144 a 1 are connected to each other. The second bankportion 144 a 1 is stacked on the first bank portion 142 a 1, and awidth of at least one of the bank structures 140 a 1 gradually decreasesfrom the first bank portion 142 a 1 to the second bank portion 144 a 1.That is to say, the width of the bank structures 140 a 1 of theembodiment can be different, and gradually decreases from the arraysubstrate 110 to the opposite substrate 120. In other embodiments, thefirst bank portion 142 a 1 may be disposed above the array substrate110, and the second bank portion 144 a 1 may be disposed above theopposite substrate 120. Alternatively, both the first bank portion 142 a1 and the second bank portion 144 a 1 are disposed above the oppositesubstrate 120, and is not limited thereto. When preparing the displaydevice 100 a, the micro light-emitting diodes 130, the first bankportion 142 a 1, and the second bank portion 144 a 1 might be formed onthe array substrate 110 with no specific disposing order.

More specifically, as shown in FIG. 1A, the first bank portion 142 a 1has a first bottom surface 141 a 1 and a first side surface 143 a 1connected to the first bottom surface 141 a 1, and a first includedangle A11 is formed between the first side surface 143 a 1 and the firstbottom surface 141 a 1. The first bottom surface 141 a 1 is a surface ofthe first bank portion 142 a 1 adjacent to the array substrate 110. Thesecond bank portion 144 a 1 has a second bottom surface 145 a 1 and asecond side surface 147 a 1 connected to the second bottom surface 145 a1, the second bottom surface 145 a 1 is a surface of the second bankportion 144 a 1 away from the array substrate 110, and a second includedangle A12 is formed between the second side surface 147 a 1 and thesecond bottom surface 145 a 1. In an embodiment, the first includedangle A11 and the second included angle A12 are between 30 degrees and150 degrees but not equal to 90 degrees respectively, for example. Asshown in FIG. 1A, exterior contours of both the first bank portion 142 a1 and the second bank portion 144 a 1 are trapezoids, and the firstincluded angle A11 is different from the second included angle A12. Forexample, the first included angle A11 is less than the second includedangle A12. In other embodiments, referring to FIG. 1B, a bank structure140 a 2 includes at least a first bank portion 142 a 2 and a second bankportion 144 a 2. The first bank portion 142 a 2 has a first bottomsurface 141 a 2 and a first side surface 143 a 2 connected to the firstbottom surface 141 a 2, and a first included angle A21 is formed betweenthe first side surface 143 a 2 and the first bottom surface 141 a 2. Thesecond bank portion 144 a 2 has a second bottom surface 145 a 2 and asecond side surface 147 a 2 connected to the second bottom surface 145 a2, and a second included angle A22 is formed between the second sidesurface 147 a 2 and the second bottom surface 145 a 2. In an embodiment,the first included angle A21 may also be equal to the second includedangle A22. In other embodiments, if the first bank portion 142 a 2 andthe second bank portion 144 a 2 are formed by the same material, thebank structure 140 a 2 may also be an integrally formed structure(namely, there is no boundary between the first bank portion 142 a 2 andthe second bank portion 144 a 2). A height of at least one the bankstructure 140 a 2 may be more than or equal to the height of at leastone of the micro light-emitting diodes 130, and is not limited thereto.

It should be noted that, the exterior contours of the bank structures140 a 1 and 140 a 2 are not limited by the embodiment, even though thefirst bank portions 142 a 1, 142 a 2 and the second bank portions 144 a1, 144 a 2 depicted here are all regular trapezoids and have the firstside surfaces 143 a 1, 143 a 2 and the second side surfaces 147 a 1, 147a 2 respectively. However, in other embodiments, referring to FIG. 1C, afirst bank portion 142 a 3 of a bank structure 140 a 3 has a firstbottom surface 141 a 3 and a first curved surface 143 a 3 connected tothe first bottom surface 141 a 3, and a second bank portion 144 a 3 hasa second bottom surface 145 a 3 and a second curved surface 147 a 3connected to the second bottom surface 145 a 3, wherein the first curvedsurface 143 a 3 and the second curved surface 147 a 3 are connected toeach other. Alternatively, referring to FIG. 1D, a first bank portion142 a 4 of a bank structure 140 a 4 has a first bottom surface 141 a 4and a first concave-convex surface 143 a 4 connected to the first bottomsurface 141 a 4, and a second bank portion 144 a 4 has a second bottomsurface 145 a 4 and a second concave-convex surface 147 a 4 connected tothe second bottom surface 145 a 4, wherein the first concave-convexsurface 143 a 4 and the second concave-convex surface 147 a 4 areconnected to each other. In short, outer surfaces of the bank structures140 a 1, 140 a 2, 140 a 3 and 140 a 4 may be an inclined surface, acurved surface (or arc surface) or an irregular surface, and is notlimited thereto.

It should be mentioned that, as shown in FIG. 1A, FIG. 1B, FIG. 1C andFIG. 1D, the first side surfaces 143 a 1, 143 a 2, 143 a 3 and 143 a 4and the second side surfaces 147 a 1, 147 a 2, 147 a 3 and 147 a 4 havethe same contour specifically. For example, they are all flat surfaces,curved surfaces or concave-convex surfaces. However, in otherembodiments not shown, the first side surfaces and the second sidesurfaces may have different contours respectively. For example, thefirst side surface is a flat surface while the second side surface is acurved surface, and is not limited thereto. Additionally, the firstincluded angles A11 and A21 and the second included angles A12 and A22are between 30 degrees and 150 degrees but not equal to 90 degreesrespectively, for example. Also, the first included angles A11, A21 andthe second included angles A12, A22 may be the same or different, and isnot limited thereto.

Additionally, a material of the first bank portions 142 a 1, 142 a 2,142 a 3 and 142 a 4 and the second bank portions 144 a 1, 144 a 2, 144 a3 and 144 a 4 of the bank structures 140 a 1, 140 a 2, 140 a 3 and 140 a4 may be the same or different, which can be comprised of anypatternable gel material, wherein the material comprises, for example, ablack photoresist, a white photoresist, a transparent material dopedwith a scattering material, a transparent material coated with areflective film, or a photo spacer. For instance, referring to FIG. 1A,if the first bank portion 142 a 1 comprises a black photoresist and thesecond bank portion 144 a 1 comprises a white photoresist, the firstbank portion 142 a 1 can absorb the light with larger angle emitted fromthe micro light-emitting diodes 130 to the array substrate 110, so as toprevent the light with larger angle from generating a specific anglereflection after reflecting from the array substrate 110, therebyaffecting visual effects. The second bank portions 144 a 1 can guidelights emitted from side walls of the micro light-emitting diodes 130 tobe transmitted along a normal direction so as to improve thelight-emitting efficiency of the micro light-emitting diodes 130 andadjust the light-emitting viewing angle of the micro light-emittingdiodes 130.

In short, since the display device 100 a of the embodiment comprises thebank structures 140 a 1, the optical cross-talk phenomenon generated bythe micro light-emitting diodes 130 arranged in an array on the arraysubstrate 110 can be effectively reduced. Thereby, the optical displayperformance of the display device 100 a of the embodiment can beeffectively improved. Additionally, the bank structures 140 a 1 arecomposed of the first bank portion 142 a 1 and the second bank portion144 a 1 connected to each other, and thus the material of the first bankportion 142 a 1 and the second bank portion 144 a 1, the angle design ofthe first included angle A11 and the second included angle A12 and theposition where the first bank portion 142 a 1 and the second bankportion 144 a 1 disposed can be chosen by users according to theirneeds. For example, the first bank portion 142 a 1 and the second bankportion 144 a 1 are both disposed above the array substrate 110 or theopposite substrate 120. Alternatively, at least one of the first bankportion 142 a 1 and the second bank portion 144 a 1 is disposed abovethe array substrate 110, and at least another one of the first bankportion 142 a 1 and the second bank portion 144 a 1 is disposed abovethe opposite substrate 120. In other words, the bank structures 140 a 1of the embodiment has a wider flexibility of the design, and the microlight-emitting diodes 130 may have better light-emitting efficiency bythe design of the bank structures 140 a 1, such that the display device100 a of the embodiment has a better optical display performance.

It should be noted that, the component notations and partial details ofthe structures hereinafter provided in the embodiments can be the sameas or similar to the previous embodiment, wherein the same notationsrepresent the same or similar components while the repeated same detailsare omitted, which can refer to the previous embodiment.

FIG. 2 is a schematic cross-sectional view of a display device accordingto another embodiment. Referring to FIG. 2, a display device 100 b ofthe embodiment is similar to the display device 100 a of FIG. 1A, andthe difference therebetween is that, at least one of bank structures 140b of the embodiment includes at least a first bank portion 142 b and asecond bank portion 144 b, wherein the first bank portion 142 b isdisposed above the array substrate 110, and the second bank portion 144b is disposed above the opposite substrate 120. The first bank portion142 b and the second bank portion 144 b are connected to each other. Awidth of the first bank portion 142 b gradually decreases from the arraysubstrate 110 to the opposite substrate 120, and a width of the secondbank portion 144 b gradually decreases from the opposite substrate 120to the array substrate 110. Also, after the combination of the arraysubstrate 110 and the opposite substrate 120, the first bank portion 142b is connected to the second bank portion 144 b. Thus, the opticalcross-talk phenomenon generated by the micro light-emitting diodes 130can be significantly reduced, so as to effectively improve the opticaldisplay performance of the display device 100 b of the embodiment.

FIG. 3 is a schematic cross-sectional view of a display device accordingto another embodiment. Referring to FIG. 3, a display device 100 c ofthe embodiment is similar to the display device 100 a of FIG. 1A, andthe difference therebetween is that, the display device 100 c of theembodiment further includes an optical coating layer 150 disposed abovean outer surface of at least one of the bank structures 140 a 1. Asshown in FIG. 3, the optical coating layer 150 covers the first sidesurface 143 a 1 of the first bank portion 142 a 1 and the second sidesurface 147 a 1 of the second bank portion 144 a 1. If the opticalcoating layer 150 comprises a reflective material (e.g., silver,aluminum or chromium, and is not limited thereto), the light-emittingefficiency of the micro light-emitting diodes 130 can be effectivelyincreased. However, if the optical coating layer 150 comprises a lightabsorbing material (e.g., chromium, chromium nitride, chromium oxide,aluminum alloy or aluminum nitride, and is not limited thereto), straylight can be effectively reduced. In other embodiments, the opticalcoating layer 150 may also cover on a portion of the outer surface of atleast one of the bank structures 140 a 1, and is not limited thereto.

FIG. 4 is a schematic cross-sectional view of a display device accordingto another embodiment. Referring to FIG. 4, a display device 100 d ofthe embodiment is similar to the display device 100 c of FIG. 3, and thedifference therebetween is that, the micro light-emitting diodes of theembodiment can emit light with the same color, such as blue light microlight-emitting diodes 130 a. Furthermore, the display device 100 d ofthe embodiment further includes a wavelength converting material 160 anda plurality of color filter patterns 172, 174 and 176. The wavelengthconverting material 160 is disposed in at least one of the accommodatingregions C, and covers at least the blue light micro light-emittingdiodes 130 a, wherein the wavelength converting material 160 comprisesphosphors or quantum dots (QD), for example. Specifically, thewavelength converting material 160 might be composed of the phosphors orthe quantum dots dispersed in a matrix, or the wavelength convertingmaterial 160 might be composed of only the phosphors or the quantum dotswithout a matrix, and is not limited thereto. The phosphors may beyellow phosphors, a mixture of green phosphors and red phosphors, or agreen phosphor layer stacked with a red phosphor layer, and is notlimited thereto. The quantum dots may be yellow quantum dots, a mixtureof green quantum dots and red quantum dots, or a green quantum dot layerstacked with a red quantum dot layer, and is not limited thereto. Thecolor filter patterns 172, 174 and 176 are disposed above the oppositesubstrate 120 and have at least two different colors, such as blue,green or red, wherein at least one of the color filter patterns 172, 174and 176 may also be transparent, and is not limited thereto. That is tosay, the display device 100 d of the embodiment is the use of the bluelight micro light-emitting diodes 130 a with the blue color filterpattern 172, the green color filter pattern 174 and the red color filterpattern 176 to achieve full-color display effects. The blue color filterpattern 172 of the embodiment may be a color filter pattern whichexhibits blue color, or may be a transparent material. Additionally,since the optical coating layer 150 (herein, a reflective material)covering the outer surface of the bank structures 140 a 1 can increasethe light path of blue light emitted from the blue light microlight-emitting diodes 130 a in the wavelength converting material 160,the conversion efficiency of blue light can be increased. Also, thecombination of the optical coating layer 150 and the wavelengthconverting material 160 can prevent lateral light of the blue lightmicro light-emitting diodes 130 a from absorbing to reduce an amount ofemitted-light of the blue light micro light-emitting diodes 130 a. Inshort, the display device 100 d of the embodiment may have a betteroptical display performance.

FIG. 5 is a schematic cross-sectional view of a display device accordingto another embodiment. Referring to FIG. 5, a display device 100 e ofthe embodiment is similar to the display device 100 c of FIG. 3, and thedifference therebetween is that, the display device 100 e of theembodiment further includes a scattering material 165 disposed in atleast one of the accommodating regions C and covering at least the microlight-emitting diodes 130. Here, the scattering material 165 comprisestitanium dioxide, for example, and the purpose thereof is to adjust thelight shape (light-emitting angle) of the micro light-emitting diodes130, or to increase the light-emitting angle of the micro light-emittingdiodes 130.

FIG. 6 is a schematic cross-sectional view of a display device accordingto another embodiment. Referring to FIG. 6, a display device 100 f ofthe embodiment is similar to the display device 100 c of FIG. 3, and thedifference therebetween is that, the micro light-emitting diodes of theembodiment can emit light with the same color, such as the blue lightmicro light-emitting diodes 130 a. Furthermore, accommodating regions C′of the embodiment include a plurality of first accommodating regions C1and a plurality of second accommodating regions C2. The display device100 f further includes the plurality of color filter patterns 172, 174and 176, the scattering material 165 and the wavelength convertingmaterial 160. The color filter patterns 172, 174 and 176 are disposedabove the opposite substrate 120 and have at least two different colors,such as blue, green or red. It may also be transparent. For instance,the color filter pattern 172 of the embodiment may be a color filterpattern which exhibits blue color, or may be a transparent material. Thescattering material 165 is disposed in the first accommodating regionsC1, and the wavelength converting material 160 is disposed in the secondaccommodating regions C2, wherein the scattering material 165 and thewavelength converting material 160 cover the blue light microlight-emitting diodes 130 a. Here, the purpose of the scatteringmaterial 165 is to adjust the light shape (light-emitting angle) of theblue light micro light-emitting diodes 130 a, or to increase thelight-emitting angle of the blue light micro light-emitting diodes 130a. The wavelength converting material 160 comprises phosphors or quantumdots, for example. Blue light emitted from the blue light microlight-emitting diodes 130 a may enable the display device 100 f to havea high color saturation performance by the wavelength convertingmaterial 160 and the color filter patterns 174 and 176 with differentcolors (e.g., green and red).

FIG. 7 is a schematic cross-sectional view of a display device accordingto another embodiment. Referring to FIG. 7, a display device 100 g ofthe embodiment is similar to the display device 100 d of FIG. 4, and thedifference therebetween is that, the display device 100 g of theembodiment further includes a filter pattern layer 190 disposed abovethe opposite substrate 120 and having a plurality of filter patterns192, 194 and 196, wherein the filter patterns 192, 194 and 196 aredisposed corresponding to the color filter patterns 172, 174 and 176respectively. Specifically, the filter pattern 192 is disposed betweenthe blue color filter pattern 172 and the blue light microlight-emitting diodes 130 a, the filter pattern 194 is disposed betweenthe green color filter pattern 174 and the blue light microlight-emitting diodes 130 a, and the filter pattern 196 is disposedbetween the red color filter pattern 176 and the blue light microlight-emitting diodes 130 a. The color filter pattern 172 is disposedbetween the filter pattern 192 and the opposite substrate 120, the colorfilter pattern 174 is disposed between the filter pattern 194 and theopposite substrate 120, and the color filter pattern 176 is disposedbetween the filter pattern 196 and the opposite substrate 120. Thefilter patterns of the embodiment may be band pass filters.Specifically, the filter patterns 192, 194 and 196 allow light in aspecific wavelength range to pass, and light in other non-specificwavelength range will be reflected. For instance, the filter pattern 192allows blue light to penetrate, the filter pattern 194 allows greenlight to penetrate, and the filter pattern 196 allows red light topenetrate. When light in a specific wavelength range passes the filterpatterns 192, 194 and 196, and light in non-specific wavelength range isreflected back to the wavelength converting material 160, reflectedlight will excite the wavelength converting material 160 again such thatexcitation light will pass the filter patterns 192, 194 and 196 again.Thereby, light conversion ratio of the blue light micro light-emittingdiodes 130 a can be improved, and the required thickness of thewavelength converting material 160 can be reduced. In other embodiments,the filter patterns 192, 194 and 196 may also be high pass filters orlow pass filters, and is not limited thereto.

FIG. 8A is a schematic cross-sectional view of a display deviceaccording to another embodiment. FIG. 8B is a schematic top view of apatterned reflective layer of FIG. 8A. Referring to FIG. 8A and FIG. 8Bat the same time, a display device 100 h of the embodiment is similar tothe display device 100 d of FIG. 4, and the difference therebetween isthat, the display device 100 h of the embodiment further includes apatterned reflective layer 210 disposed above the opposite substrate 120and having a plurality of reflective patterns 212, wherein the colorfilter patterns 172, 174 and 176 are located between the patternedreflective layer 210 and the opposite substrate 120. A distributiondensity of the reflective patterns 212 changes with the color filterpatterns 172, 174 and 176 corresponding to different colors. Morespecifically, the blue color filter pattern 172, the green color filterpattern 174 and the red color filter pattern 176 are located in a firstsub-pixel region P1, a second sub-pixel region P2 and a third sub-pixelregion P3 respectively. The reflective patterns 212 reflect the bluelight emitted from the blue light micro light-emitting diodes 130 a backto the at least one of the accommodating regions C, and the blue lightwill further be reflected towards the patterned reflective layer 210.Regions around the reflective patterns 212 allow the blue light emittedfrom the blue light micro light-emitting diodes 130 a to pass throughthe patterned reflective layer 210. The distribution density of thereflective pattern 212 located in the third sub-pixel region P3 is morethan the distribution density of the reflective pattern 212 located inthe second sub-pixel region P2, and the distribution density of thereflective pattern 212 located in the second sub-pixel region P2 is morethan the distribution density of the reflective pattern 212 located inthe first sub-pixel region P1. That is to say, the distribution densityof the reflective pattern 212 gradually increases from the blue colorfilter pattern 172 to the green color filter pattern 174 and the redcolor filter pattern 176. That is, blue light emitted from the bluelight micro light-emitting diodes 130 a has different light paths indifferent sub-pixel regions by the distribution density of thereflective pattern 212, thereby improving the optical displayperformance of the display device 100 h.

Additionally, referring to FIG. 8A, the patterned reflective layer 210of the embodiment specifically includes a first patterned reflectivelayer 210 a and a second patterned reflective layer 210 b. The secondpatterned reflective layer 210 b is located between the first patternedreflective layer 210 a and the color filter patterns 172, 174 and 176. Amaterial of the first patterned reflective layer 210 a comprises a metalmaterial having a reflectivity more than 70%, such as silver, aluminumor chromium, and a material of the second patterned reflective layer 210b comprises a light absorbing material, such as chromium oxide, chromiumnitride, aluminum oxide or aluminum nitride, and is not limited thereto.That is to say, the patterned reflective layer 210 of the embodiment iscomposed of a structural layer stacked by a plurality of layers.However, in other embodiments not shown, the patterned reflective layermay also be a single-layer structural layer, and the material thereofcomprises, for example, a high reflectivity material of silver layers oraluminum layers, which is still within the scope of the embodiment.Here, the purpose of the first patterned reflective layer 210 a is toenable the blue light micro light-emitting diodes 130 a to be reflectedso as to excite the wavelength converting material 160 again, and thepurpose of the second patterned reflective layer 210 b is to prevent thefirst patterned reflective layer 210 a from irradiating by externallight directly which may cause a reduction of contrast.

FIG. 9A is a schematic cross-sectional view of a display deviceaccording to another embodiment. Referring to FIG. 9A, a display device100 i of the embodiment is similar to the display device 100 f of FIG.6, and the difference therebetween is that, the display device 100 i ofthe embodiment further includes a wavelength converting enhancementlayer 180 disposed between the color filter patterns 174 and 176 and thewavelength converting material 160, and between the color filter pattern172 and the scattering material 165, which can effectively improve lightconversion ratio of light emitted from the blue light microlight-emitting diodes 130 a.

FIG. 9B is a curve diagram illustrating a relationship betweenwavelength and normalized light intensity of the display device with thewavelength converting enhancement layer 180 and without the wavelengthenhancement converting layer 180 of FIG. 9A. The curve T1 represents thedisplay device not provided with the wavelength converting enhancementlayer 180; while the curve T2 represents the display device 100 iprovided with the wavelength converting enhancement layer 180. The curveT1 and the curve T2 is a compared spectrogram which have been normalizedwith blue light peak (wavelength of about 430 nm to 480 nm). As shown inFIG. 9B, the display device 100 i with the wavelength convertingenhancement layer 180 can effectively improve the light conversionefficiency of light emitted from the blue light micro light-emittingdiodes 130 a compared with the display device provided without thewavelength converting enhancement layer 180.

It should be noted that, the wavelength converting enhancement layer 180of the embodiment may be the filter pattern layer 190 in FIG. 7 or thepatterned reflective layer 210 in FIG. 8A and FIG. 8B, for example.Definitely, the wavelength converting enhancement layer 180 of theembodiment may also be a microstructural layer 180 a comprised of aplurality of high reflectivity patterns 182 and a plurality of lowreflectivity patterns 184 in FIG. 9C, wherein the light reflection pathof the corresponding region can be changed by the setting density of thehigh reflectivity patterns 182 and the low reflectivity patterns 184.Specifically, since the high reflectivity patterns 182 is more likely toreflect light than the low reflectivity patterns 184 in themicrostructural layer 180 a. The microstructural layer 180 a is similarto the patterned reflective layer 210 in FIG. 8A, which can enable lightemitted from the micro light-emitting diode to have different lightpaths in different sub-pixel regions by the distribution density of thehigh reflectivity patterns 182, thereby improving the optical displayperformance of the display device. Alternatively, the wavelengthconverting enhancement layer 180 of the embodiment may also be amicrostructural layer 180 b doped with scattering particles 186 in FIG.9D, wherein the light reflection path of the corresponding region can bechanged by the distribution density of the scattering particles 186.Specifically, light will be scattered when meets the scatteringparticles 186, and thus the microstructural layer 180 b enables lightemitted from the micro light-emitting diode to have different lightpaths in different sub-pixel regions by the distribution density of thescattering particles 186, thereby improving the optical displayperformance of the display device, wherein the scattering particles 186comprise titanium dioxide, for example.

FIG. 10 is a schematic cross-sectional view of a display deviceaccording to another embodiment. Referring to FIG. 10, a display device100 j of the embodiment is similar to the display device 100 i of FIG.9A, and the difference therebetween is that, the micro light-emittingdiodes of the embodiment can emit light with different colorsspecifically, such as the blue light micro light-emitting diodes 130 aand the green light micro light-emitting diodes 130 b, wherein the greenlight micro light-emitting diodes 130 b are located between the bluelight micro light-emitting diodes 130 a. As shown in FIG. 10, the secondaccommodating regions C2 corresponding to the red color filter pattern176 are disposed with the wavelength converting material 160, while thefirst accommodating regions C1 corresponding to the blue color filterpattern 172 and corresponding to the green color filter pattern 174 aredisposed with the scattering material 165. In the embodiment, the colorfilter pattern 172 corresponding to blue and the color filter pattern174 corresponding to green may be color filter patterns having color(e.g., blue and green), and may also be a transparent material.

FIG. 11 is a schematic cross-sectional view of a display deviceaccording to another embodiment. Referring to FIG. 11, a display device100 k of the embodiment is similar to the display device 100 b of FIG.2, and the difference therebetween is that, the micro light-emittingdiodes of the embodiment can emit light with the same colorspecifically, such as the blue light micro light-emitting diodes 130 a.A first bank portion 142 b 1 disposed above the array substrate 110 ofthe embodiment has a first bottom surface 141 b 1 relatively far awayfrom the opposite substrate 120, and a second bank portion 144 b 1disposed above the opposite substrate 120 has a second bottom surface145 b 1 relatively far away from the array substrate 110, wherein awidth W1 of the first bottom surface 141 b is less than a width W2 ofthe second bottom surface 145 b 1, and is not limited thereto. In otherembodiments not shown, the width W1 of the first bottom surface 141 b 1may also be more than or equal to the width W2 of the second bottomsurface 145 b 1. As shown in FIG. 11, a width of the first bank portion142 b 1 gradually decreases from the array substrate 110 to the oppositesubstrate 120, and a width of the second bank portion 144 b 1 graduallydecreases from the opposite substrate 120 to the array substrate 110.Thus, a necking portion is formed at the junction of the first bankportion 142 b 1 and the second bank portion 144 b 1. In otherembodiment, a discontinuous interface is formed at the necking portionof the first bank portion 142 b 1 and the second bank portion 144 b 1,and is not limited thereto.

Furthermore, the display device 100 k of the embodiment further includesa filler material 167, the wavelength converting material 160, theplurality of color filter patterns 172, 174 and 176 and the wavelengthconverting enhancement layer 180. The filler material 167 is disposed inat least one of the accommodating regions C around at least one of theblue light micro light-emitting diodes 130 a, and exposing an uppersurface 132 of at least one of the blue light micro light-emittingdiodes 130 a relatively far away from the array substrate 110. Thewavelength converting material 160 is disposed in at least one of theaccommodating regions C, and covers at least the filler material 167 andthe upper surface 132 of at least one of the blue light microlight-emitting diodes 130 a. The color filter patterns 172, 174 and 176are disposed above the opposite substrate 120 and have at least twodifferent colors, such as blue light, green light or red light. It mayalso be transparent. The wavelength converting enhancement layer 180 isdisposed between the color filter patterns 172, 174 and 176 and thewavelength converting material 160. Here, the wavelength convertingenhancement layer 180 is the filter pattern layer 190 in FIG. 7, thepatterned reflective layer 210 in FIG. 8A and FIG. 8B, themicrostructural layer 180 a in FIG. 9C, or the microstructural layer 180b in FIG. 9D. A material of the wavelength converting enhancement layer180 comprises titanium dioxide or silicon dioxide, for example, and isnot limited thereto.

Since bank structures 140 b 1 of the embodiment are composed of thefirst bank portion 142 b 1 and the second bank portion 144 b 1, whereinthe design of the necking is formed between the first bank portion 142 b1 and the second bank portion 144 b 1, re-reflection probability oflight emitted from the blue light micro light-emitting diodes 130 a canbe effectively increased, thereby effectively improving the opticaldisplay performance of the overall display device 100 k.

Additionally, the filler material 167 of the embodiment is a scatteringmaterial or a light absorbing material, for example, and the purposethereof is to protect the surroundings of the blue light microlight-emitting diodes 130 a. The wavelength converting material 160 isphosphors or quantum dots, for example.

FIG. 12 is a schematic cross-sectional view of a display deviceaccording to another embodiment. Referring to FIG. 12, a display device100 m of the embodiment is similar to the display device 100 k of FIG.11, and the difference therebetween is that, a width of a first bankportion 142 b 2 of bank structures 140 b 2 of the embodiment graduallyincreases from the array substrate 110 to the opposite substrate 120,and a width of a second bank portion 144 b 2 gradually decreases fromthe opposite substrate 120 to the array substrate 110. Thus, adiscontinuous interface is formed at the junction of the first bankportion 142 b 2 and the second bank portion 144 b 2.

FIG. 13 is a schematic cross-sectional view of a display deviceaccording to another embodiment. Referring to FIG. 13, a display device100 n of the embodiment is similar to the display device 100 k of FIG.11, and the difference therebetween is that, a width of a first bankportion 142 b 3 of bank structures 140 b 3 of the embodiment graduallyincreases from the array substrate 110 to the opposite substrate 120,and a width of a second bank portion 144 b 3 gradually increases fromthe opposite substrate 120 to the array substrate 110. Thus, adiscontinuous interface is formed at the junction of the first bankportion 142 b 3 and the second bank portion 144 b 3.

It should be mentioned that, although the optical coating layer 150 isdepicted in the embodiments of FIG. 3 to FIG. 13, the display device maynot have the optical coating layer in other embodiments not shown. Thatis to say, the optical coating layer is a selective element layer, notan essential element layer.

FIG. 14 is a schematic cross-sectional view of a display deviceaccording to another embodiment. Referring to FIG. 14, a display device100 p of the embodiment is similar to the display device 100 a of FIG.1A, and the difference therebetween is that, at least one of bankstructures 140 c includes a first bank structure 140 c 1 and a secondbank structure 140 c 2. The first bank structure 140 c 1 and the secondbank structure 140 c 2 are disposed above the array substrate 110, andthe first bank structure 140 c 1 and the second bank structure 140 c 2have a first air gap G1 therebetween. Furthermore, the bank structures140 c and the opposite substrate 120 have a second air gap G2therebetween. The opposite substrate 120 includes a plurality of lightabsorbing patterns 122, and the light absorbing patterns 122 are locatedin the second air gap G2.

Specifically, the first bank structure 140 c 1 has a first flat surface141 c and a first inclined surface 143 c opposite to each other. Thesecond bank structure 140 c 2 has a second flat surface 145 c and asecond inclined surface 147 c opposite to each other. The first inclinedsurface 143 c faces the second inclined surface 147 c. The first bankstructure 140 c 1 and the second bank structure 140 c 2 have the firstair gap G1 therebetween, and at least one of the light absorbingpatterns 122 is disposed corresponding to at least one the first air gapG1. A width of the first bank structure 140 c 1 and a width of thesecond bank structure 140 c 2 gradually increase from the arraysubstrate 110 to the opposite substrate 120. More specifically, thefirst inclined surface 143 c and the array substrate 110 have a firstincluded angle A31 therebetween, and the second inclined surface 147 cand the array substrate 110 have a second included angle A32therebetween. It should be noted that, the included angle A31 and theincluded angle A32 represent the angles outside the first bankstructures 140 c 1 as shown in FIG. 14. The first included angle A31 isequal to the second included angle A32. In an embodiment, the firstincluded angle is more than or equal to 30 degrees and less than 90degrees. In other embodiments, the first included angle A31 may not beequal to the second included angle A32, and is not limited thereto.

Additionally, the display device 100 p of the embodiment furtherincludes a protective layer 220 disposed above the micro light-emittingdiodes 130 and a top surface 142 c of the bank structures 140 crelatively far away from the array substrate 110, which can effectivelyprotect the micro light-emitting diodes 130 from the invasion ofmoisture and oxygen. Here, a material of the protective layer 220includes an organic material, an inorganic material or a combination ofan organic material and an inorganic material. As shown in FIG. 14, theprotective layer 220 of the embodiment is a single-layer structurallayer specifically. However, in other embodiments not shown, theprotective layer 220 may also be a multi-layer structural layer, such asa stacked layer of silicon oxide or aluminum oxide and silicon nitride,or a stacked layer of an inorganic material and an organic material;however, it is not limited thereto.

Since the first bank structure 140 c 1 and the second bank structure 140c 2 of the embodiment have the first air gap G1 therebetween, lightsemitted from side walls of the micro light-emitting diodes 130 can betotally reflected by the structure design of the first bank structure140 c 1 and the second bank structure 140 c 2, such as light beam L.Thus, a higher portion of lights emitted from the side walls of themicro light-emitting diodes 130 can be guided to be emitted along anormal direction by total reflection. The light-emitting efficiency canbe increased, and the optical cross-talk effects can be reduced.

It should be noted that, in other embodiments not shown, the bankstructures 140 a 1, 140 a 2, 140 a 3, 140 a 4, 140 b, 140 b 1, 140 b 2,140 b 3 and 140 c, the opposite substrate 120, the optical coating layer150, the wavelength converting material 160, the scattering material165, the filler material 167, the color filter patterns 172, 174 and176, the filter patterns 192, 194 and 196, the patterned reflectivelayer 210, the microstructural layers 180 a and 180 b and the protectivelayer 220 mentioned in the embodiments can also be selected. Theopposite substrate 120 might comprise a plurality of black matrixbetween different filter patterns or different color filter patterns todecrease an optical cross-talk phenomenon, and is not limited thereto.In other embodiments, the micro light-emitting diodes can be replacedentirely or partially by organic light-emitting diodes (OLED), liquidcrystal (LC), quantum dot (QD) or other display elements, and is notlimited thereto. The display device might also be a flexible display, atouch display, or a curved display, and is not limited thereto. Theaforesaid components could be selected and combined according to theactual requirements in order to achieve the desirable technical effects.

In summary, since the display device of the embodiment has the design ofthe bank structures, the optical cross-talk phenomenon generated by themicro light-emitting diodes arranged in an array on the array substratecan be effectively reduced. Thereby, the optical display performance ofthe display device of the embodiment can be effectively improved.

Although the embodiment has been described, the modifications may bemade without departing from the spirit of the embodiment. Accordingly,the scope of the embodiment is defined by the attached claims not by theabove detailed descriptions.

What is claimed is:
 1. A display device, comprising: an array substrate;a plurality of micro light-emitting diodes arranged in an array on thearray substrate; a plurality of bank structures located on the arraysubstrate, wherein the plurality of micro light-emitting diodes areelectrically connected to the array substrate, the plurality of bankstructures form a plurality of accommodating regions, one of theplurality of micro light-emitting diodes is located in one of theplurality of accommodating regions, one of the plurality of bankstructures comprises a first bank portion and a second bank portion, thefirst bank portion has a first bottom surface and a first side surfaceconnected to the first bottom surface, the first bottom surface is asurface of the first bank portion adjacent to the array substrate, thesecond bank portion has a second bottom surface and a second sidesurface connected to the second bottom surface, the second bottomsurface is a surface of the second bank portion away from the arraysubstrate, and a height of the one of the plurality of bank structuresis more than or equal to a height of the one of the plurality of microlight-emitting diodes; and an optical coating layer disposed on asurface of the one of the plurality of bank structures.
 2. The displaydevice according to claim 1, wherein a first included angle is formedbetween the first side surface and the first bottom surface, the firstincluded angle is between 30 degrees and 150 degrees but not equal to 90degrees.
 3. The display device according to claim 2, wherein a secondincluded angle is formed between the second side surface and the secondbottom surface, and the second included angle is between 30 degrees and150 degrees but not equal to 90 degrees, wherein the first bank portionand the second bank portion are connected to each other, the firstincluded angle is different from the second included angle.
 4. Thedisplay device according to claim 1, further comprising: a protectivelayer disposed above the one of the plurality of micro light-emittingdiodes.
 5. The display device according to claim 1, further comprising:a scattering material disposed in the one of the plurality ofaccommodating regions, and covering the one of the plurality of microlight-emitting diodes.
 6. The display device according to claim 1,further comprising: a wavelength converting material disposed in the oneof the plurality of accommodating regions, and covering the one of theplurality of micro light-emitting diodes.
 7. A display device,comprising: an array substrate; an opposite substrate disposed oppositeto the array substrate; a plurality of micro light-emitting diodesarranged in an array on the array substrate; a plurality of bankstructures located between the array substrate and the oppositesubstrate, wherein the plurality of micro light-emitting diodes areelectrically connected to the array substrate, the plurality of bankstructures form a plurality of accommodating regions, one of theplurality of micro light-emitting diodes is located in one of theplurality of accommodating regions, one of the plurality of bankstructures comprises a first bank structure and a second bank structure,the first bank structure has a first flat surface and a first inclinedsurface opposite to each other, the second bank structure has a secondflat surface and a second inclined surface opposite to each other, thefirst inclined surface faces the second inclined surface, a first airgap is formed between the first bank structure and the second bankstructure, a width of the first bank structure and a width of the secondbank structure gradually increase from the array substrate to theopposite substrate, a first included angle is formed between the firstinclined surface and the array substrate, a second included angle isformed between the second inclined surface and the array substrate, andthe first included angle and the second included angle are more than orequal to 30 degrees and less than 90 degrees, and a height of the one ofthe plurality of bank structures is more than or equal to a height ofthe one of the plurality of micro light-emitting diodes; and an opticalcoating layer disposed on a surface of the one of the plurality of bankstructures.
 8. The display device according to claim 7, furthercomprising: a scattering material disposed in the one of the pluralityof accommodating regions, and covering the one of the plurality of microlight-emitting diodes.
 9. The display device according to claim 7,further comprising: a wavelength converting material disposed in the oneof the plurality of accommodating regions, and covering the one of theplurality of micro light-emitting diodes.
 10. The display deviceaccording to claim 9, further comprising: a color filter layer disposedabove the opposite substrate and having a plurality of color filterpatterns.
 11. The display device according to claim 7, furthercomprising: a filler material disposed in the one of the plurality ofaccommodating regions around the one of the plurality of microlight-emitting diodes, and exposing an upper surface of the one of theplurality of micro light-emitting diodes relatively far away from thearray substrate; and a wavelength converting material disposed in theone of the plurality of accommodating regions, and covering the fillermaterial and the upper surface of the one of the plurality of microlight-emitting diodes.
 12. The display device according to claim 11,further comprising: a color filter layer disposed above the oppositesubstrate and having a plurality of color filter patterns.
 13. Thedisplay device according to claim 7, wherein a second air gap is formedbetween the plurality of bank structures and the opposite substrate, theopposite substrate comprises a plurality of light absorbing patterns,the plurality of light absorbing patterns are located in the second airgap, and one of the plurality of light absorbing patterns is disposedcorresponding to one of the first air gap.
 14. The display deviceaccording to claim 13, further comprising: a protective layer disposedabove the one of the plurality of micro light-emitting diodes and a topsurface of the one of the plurality of bank structures relatively faraway from the array substrate.